Analysis by: RonJay Kristoffer Caragay
ALIASES:

TrojanDownloader:Win32/Upatre.AA (Microsoft); Trojan-Downloader.Win32.Agent.hevb (Kaspersky); Troj/Upatre-EL (Sophos); TR/Dldr.Upatre.AA.16 (Avira); Downloader.Generic13.CONS (AVG); Win32/Upatre.FUaNBRD (TotalDefense)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It does not have any propagation routine.

It does not have any backdoor routine.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

It does not have any information-stealing capability.

It deletes itself after execution.

  TECHNICAL DETAILS

Payload: Downloads files

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan drops the following copies of itself into the affected system and executes them:

  • %User Temp%\xwjfk.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}ionacastellana.com/Gestores/extra/2cr.tar
  • http://{BLOCKED}t.com/imgupload/js/2cr.tar

It saves the files it downloads using the following names:

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Information Theft

This Trojan does not have any information-stealing capability.

Other Details

This Trojan deletes itself after execution.

  SOLUTION

Minimum Scan Engine: 9.700
VSAPI OPR PATTERN File: 11.113.00
VSAPI OPR PATTERN Date: 28 Aug 2014

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Remove malware/grayware files dropped/downloaded by TROJ_UPATRE.YYOS. (Note: Please skip this step if the threats listed below have already been removed.)

Step 4

Search and delete these files

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %User Temp%\kurit.exe
  • %User Temp%\xwjfk.exe

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_UPATRE.YYOS. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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